ENH: Adds background color option to VTKViewer class

Adds background color option to VTKViewer class which
internally calls vtkRenderer

Base/Rendering/imstkVTKRenderer.cpp

@@ -100,7 +100,7 @@ VTKRenderer::VTKRenderer(std::shared_ptr<Scene> scene)
     ///TODO : based on scene properties
     // Customize background colors
     m_vtkRenderer->SetBackground(0.66,0.66,0.66);
-    m_vtkRenderer->SetBackground2(157.0/255.0*0.66, 186/255.0*0.66, 192.0/255.0*0.66);
+    m_vtkRenderer->SetBackground2(0.406, 0.481, 0.497);
     m_vtkRenderer->GradientBackgroundOn();
 
     ///TODO : only on deformable objects with UseBounds (need vtk update)
@@ -221,7 +221,7 @@ VTKRenderer::addActors(const std::vector<vtkSmartPointer<vtkProp>>& actorList)
 }
 
 void
-VTKRenderer::updateBackground(Vec3d backgroundOne, Vec3d backgroundTwo /*= Vec3d::Zero()*/, bool gradientBackground /*= false*/)
+VTKRenderer::updateBackground(const Vec3d backgroundOne, const Vec3d backgroundTwo /*= Vec3d::Zero()*/, const bool gradientBackground /*= false*/)
 {
     m_vtkRenderer->SetBackground(backgroundOne.x(), backgroundOne.y(), backgroundOne.z());
     if (gradientBackground)

Base/Rendering/imstkVTKRenderer.h

@@ -92,8 +92,9 @@ public:
     vtkSmartPointer<vtkRenderer> getVtkRenderer() const;
 
     ///
-    /// \brief
-    void updateBackground(Vec3d color1, Vec3d color2 = Vec3d::Zero(), bool gradientBackground = false);
+    /// \brief Update background colors
+    ///
+    void updateBackground(const Vec3d color1, const Vec3d color2 = Vec3d::Zero(), const bool gradientBackground = false);
 
 protected:
     ///

Base/SimulationManager/imstkVTKViewer.cpp

@@ -253,4 +253,10 @@ VTKViewer::getScreenCaptureUtility() const
 {
     return m_screenCapturer;
 }
+
+void
+VTKViewer::setBackgroundColors(const Vec3d color1, const Vec3d color2 /*= Vec3d::Zero()*/, const bool gradientBackground /*= false*/)
+{
+    this->getCurrentRenderer()->updateBackground(color1, color2, gradientBackground);
+}
 } // imstk

Base/SimulationManager/imstkVTKViewer.h

@@ -135,15 +135,24 @@ public:
     void setOnRightButtonUpFunction(VTKEventHandlerFunction func);
     void setOnMouseWheelForwardFunction(VTKEventHandlerFunction func);
     void setOnMouseWheelBackwardFunction(VTKEventHandlerFunction func);
-    // Set custom behaviour to be run on every frame.
-    // The return of the function will not have any  effect.
+
+    ///
+    /// \brief Set custom behavior to be run on every frame.
+    /// The return of the function will not have any  effect.
+    ///
     void setOnTimerFunction(VTKEventHandlerFunction func);
 
     ///
-    /// \brief access screen shot utility
+    /// \brief Access screen shot utility
     ///
     std::shared_ptr<VTKScreenCaptureUtility> getScreenCaptureUtility() const;
 
+    ///
+    /// \brief Set the coloring of the screen background
+    /// If 'gradientBackground' is false or not supplied color1 will fill the entire background
+    ///
+    void setBackgroundColors(const Vec3d color1, const Vec3d color2 = Vec3d::Zero(), const bool gradientBackground = false);
+
 protected:
 
     vtkSmartPointer<vtkRenderWindow> m_vtkRenderWindow = vtkSmartPointer<vtkRenderWindow>::New();

Examples/Sandbox/main.cpp

@@ -1386,6 +1386,7 @@ void testPbdVolume()
     scene->addLight(light);
 
     sdk->setCurrentScene(scene);
+    sdk->getViewer()->setBackgroundColors(Vec3d(0.3285, 0.3285, 0.6525), Vec3d(0.13836, 0.13836, 0.2748), true);
     sdk->startSimulation(true);
 }